With the constant development of the variable refrigerant volume technology, a liquid reservoir, as a device for storing a liquid phase refrigerant condensed by a condenser, is unable to meet the requirement of accuracy for controlling the variable refrigerant volume, and main current manufactures remove the liquid reservoir device on the variable refrigerant volume. Due to the characteristics of the variable refrigerant volume, an outdoor unit is always operated in a partially loaded state, and a common variable refrigerant volume allow part of the refrigerant to be accommodated in volumes of the outdoor unit functioning as a condenser and an indoor unit functioning as an evaporator. However, a heat recycling variable refrigerant volume system, as a dedicated variable refrigerant volume system, is capable of simultaneously operating in two modes, i.e., a refrigerating mode and a heating mode, and the outdoor unit may be switched flexibly to function as a condenser or an evaporator according to the system mode, thus, there may be many working situations. The working conditions of the two heat exchangers may both be disadvantageous to the storage of the refrigerant, thus, an additional refrigerant adjustment mechanism may be very necessary.
Some conventional air-conditioning apparatuses have a similar device, however, the controlling is simple and the device is not adapted to the variable refrigerant volume system. Accordingly, a refrigerant adjustment device dedicated for the heat recycling variable refrigerant volume system is required, which can be controlled flexibly according to the operating condition of the refrigerant, and further ensures the reliability of the system.